Outdoor soft ground, dirt road after rain, of course, is not muddy dirt road, it will be softer, and it will hurt your knees less when running. The treadmill is very hard. If there is a suitable outdoor venue, it is naturally a good choice. Try to run on dirt roads, not on asphalt roads, especially on expressways, because the hardness of asphalt roads and expressways is very large, even greater than that of treadmills.
Running on the treadmill is a very convenient way to run, which can be realized at home, so running gene is a good choice. When we run on the treadmill, we should pay attention to adjusting our running posture, try to ensure that the forefoot touches the ground and don't use the heel. After landing, the heel will cause more damage to the knee, and the track of the treadmill is relatively wider and softer, that is, it is more elastic. The damage to the knee will be less, so the brand choice of the treadmill is still very important. Although you can enjoy the corresponding discount if you buy it online, you can't experience the comfort of the treadmill on the spot.
Generally speaking, if outdoor conditions permit, it is best to run outdoors, because if the outdoor air quality is good, good road quality will have a better guiding effect on the body and make it healthier, but running indoors is a last resort. For example, it is raining and snowing outside, and there is no suitable road surface, so it will be better to run indoors.